The theft rate of automobiles and other wheeled vehicles has stimulated the development of burglar alarm systems which are adapted to let out a noise when triggered through the actions of an intended thief in endeavoring to remove portions of a given vehicle or even to gain access thereto.
So far as I am now aware, such alarm arrangements have been heretofore actuated, that is, armed or disarmed, by either one or two techniques. Thus, by one technique, a special lock is provided somewhere on the body of the vehicle which can be opened or closed by a key controlled by an operator exteriorly located with respect to the vehicle. The lock in this case only activates or deactivates a mercury switch controlling alarm activation. The lock itself is located somewhere on the vehicle and serves no function in actually locking or unlocking portions thereof. This technique suffers from the disadvantage that any intended thief by merely inspecting exterior surfaces of the vehicle, can determine whether the vehicle is equipped with an alarm system, thereby suggesting techniques for foiling operation of the system. For example, a sharp rap of the lock itself will break the glass vial of the switch. Another disadvantage of this technique lies in the fact that a vehicle operator must not only lock up his vehicle upon leaving same, but must also separately unlock the alarm system, requiring extra time-consuming operations. A further disadvantage is that such technique requires the employment of expensive lock and key switches and installation charges.
The other technique involves a delay mechanism which permits a vehicle operator a short interval of time after unlocking, for example, a door, to enter his vehicle and accomplish engine ignition before an alarm system is triggered. This technique suffers from the disadvantage that skilled thieves require only a few seconds of time to reach and accomplish removal of expensive accessory components in an automobile. Another disadvantage lies in the fact that this technique requires expensive auxiliary equipment and associated installation charges.
So far as I am now aware, no one has heretofore provided a simple and commercially practical technique for arming and disarming alarm systems for vehicles which operates directly by merely inserting a key into a vehicular lock, such as a door lock and using such key to, for example, lock or unlock the door, thereby arming or disarming, respectively, some prechosen alarm system associated with the vehicle.